<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>盒模型之内边距</title>
    <style>
        div{
            width: 160px;
            height: 160px;
            /* 左边一个，右边一个，40，上下同理 */
            background-color: red;
            padding: 20px;
        }
    </style>
</head>
<body>
    <div>
        盒子内容content 盒子内容content 盒子内容content 盒子内容content 盒子内容content
    </div>
</body>
</html>